How to Calculate a Discount
5 min read · Updated September 26, 2026 · by the SolveCalcPro editorial team
Discounts are percentages, so a few shortcuts make sale prices easy to work out in your head. This guide covers one discount, stacked discounts and the order in which tax is added.
One discount
Sale price = price × (1 − discount%). 20% off $200: you save $40.00 and pay $160.00.
Stacked discounts do not add
20% off followed by an extra 10% is not 30% off. The second discount applies to the reduced price: $200 → $160 → $144, a combined discount of 28%.
Adding sales tax
Tax goes on the discounted price. At 8% tax on $144, the total is $155.52.
Mental shortcuts
- 10% off: move the decimal one place left and subtract.
- 25% off: pay three-quarters.
- 30% off: multiply by 0.7.
- Work backwards: if you paid $144 after 20% off, the original was 144 ÷ 0.8 = $180.
Try the discount calculator.
Practice questions
Test yourself, then tap to check. Answers are calculated by the tools linked below.
- A $120 jacket is 30% off with an extra 10% coupon and 7% tax. What is the total?
Show answer
Sale price (before tax): $75.60
- What is 35% of 240?
Show answer
35% of 240: 84
- A $64.90 receipt includes 9% sales tax. What was the price before tax?
Show answer
Price before tax (net): $59.54 · Sales tax included: $5.36
Frequently asked questions
How do I calculate a percentage discount?
Multiply the price by the percentage as a decimal to get the saving, then subtract it. Or multiply by (1 − discount).
Do two discounts add together?
No. The second applies to the already-reduced price, so the combined discount is smaller than their sum.
Is tax added before or after the discount?
Usually after: tax is charged on the discounted price.
How do I find the original price from the sale price?
Divide the sale price by (1 − discount). $144 after 20% off was 144 ÷ 0.8 = $180.
Try it yourself
Discount CalculatorWork out the sale price, the savings and the final total with tax after one or two discounts.Percentage CalculatorFind a percent of a number, percent change, and increases or decreases.
Sales Tax CalculatorAdd sales tax to a price, take it out of a total, or find the tax rate from two prices.Keep learning
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